YOKOGAWA SR1B-045N-1KC DCS Module – STARDOM FCN-RTU

YOKOGAWA SR1B-045N-1KC FCN-RTU DCS Power Supply Module: Backbone of Distributed Control Architecture

The YOKOGAWA SR1B-045N-1KC is a dedicated power supply module engineered for the STARDOM FCN-RTU (Field Control Node – Remote Terminal Unit) platform. Within a distributed control architecture, the power supply module is not a passive component — it is the electrical foundation upon which deterministic process control depends. The SR1B-045N-1KC delivers regulated DC power to the FCN-RTU backplane bus, sustaining the CPU, I/O modules, and communication interfaces under continuous industrial load conditions. Its design reflects YOKOGAWA’s engineering discipline: stable output voltage under transient load steps, internal protection circuitry against overvoltage and short-circuit faults, and thermal management suited to panel-mount environments operating across extended temperature ranges.

The STARDOM FCN-RTU platform targets applications where a full DCS infrastructure is operationally excessive but where PLC-class determinism is insufficient — oil and gas remote wellhead control, water treatment SCADA nodes, power substation automation, and chemical plant satellite control loops. In these environments, the SR1B-045N-1KC must sustain uninterrupted power delivery across AC input fluctuations typical of field power grids, without introducing noise onto the backplane that could corrupt analog I/O signal chains or communication timing.

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Technical Parameters

Hardware Logical Analysis

The SR1B-045N-1KC employs a flyback converter topology for its primary stage, chosen for its inherent galvanic isolation between the AC mains input and the DC output rails. This isolation is not incidental — it is a deliberate EMC design decision. By breaking the common-mode noise path between the field power grid and the FCN-RTU backplane, the module prevents ground-loop-induced interference from propagating into the analog signal conditioning circuits of connected I/O modules. In process plants where variable-frequency drives, solenoid valves, and high-current motor starters share the same electrical infrastructure, this isolation boundary is a measurable factor in analog measurement accuracy.

The output filter stage uses low-ESR electrolytic capacitors in parallel with ceramic bypass capacitors, creating a two-pole filter network that attenuates both low-frequency ripple (from the switching cycle) and high-frequency transients (from backplane bus switching events). The result is a 5 V logic rail with ripple held below 50 mV peak-to-peak — a specification that directly supports the signal integrity of the FCN-RTU CPU’s internal bus arbitration logic.

Thermal management relies on a combination of copper pour heat spreading on the internal PCB and a vented module housing that promotes natural convection airflow. No forced-air cooling fan is incorporated, eliminating a mechanical failure mode that would otherwise require periodic maintenance in sealed panel enclosures. The thermal derating curve allows full 45 W output up to 55 °C ambient, with linear derating to 70% output at 70 °C — a margin that accommodates panel interior temperatures in tropical industrial environments.

The overvoltage protection circuit uses a dedicated voltage supervisor IC that monitors the 5 V rail in real time. On detection of an overvoltage condition exceeding the threshold (typically 5.5–6.0 V), the supervisor triggers a latching shutdown of the PWM controller, cutting output within microseconds. This latching behavior — requiring a deliberate power cycle to reset — is an intentional design choice that prevents repeated fault cycling from masking a persistent hardware fault in the load circuit.

System Integration Benefits

• Deterministic Backplane Power Delivery: Regulated output with tight load transient response ensures CPU clock integrity and prevents spurious resets during I/O module hot-swap events on supported FCN-RTU configurations.
• Galvanic Isolation for Analog Accuracy: The AC-DC isolation barrier eliminates common-mode noise coupling from field power circuits, directly improving the signal-to-noise ratio of connected analog input modules measuring 4–20 mA process signals.
• Universal AC Input Acceptance: The 85–264 V AC input range accommodates both 110 V and 220 V field power standards without hardware modification, simplifying global deployment and spare parts standardization.
• Fanless Operation for Sealed Enclosures: Convection-cooled design eliminates fan maintenance requirements and associated MTBF reduction, supporting 24/7 continuous operation in sealed NEMA 4X or IP65 panel enclosures.
• Latching Fault Protection for Diagnostic Transparency: Latching OVP behavior forces operator acknowledgment before restart, preventing silent fault masking and ensuring that upstream fault investigation occurs before the control node is returned to service.
• Low Output Ripple for Communication Stability: Sub-50 mV ripple on the logic rail supports stable operation of the FCN-RTU’s Ethernet and serial communication interfaces, which are sensitive to power supply noise at frequencies overlapping their clock domains.
• Drop-In Replacement Compatibility: The SR1B-045N-1KC is a factory-designated PSU module for the FCN-RTU base unit, ensuring mechanical, electrical, and firmware compatibility without system reconfiguration or parameter adjustment.
• Reduced Spare Parts Inventory Complexity: A single PSU module type supports multiple FCN-RTU base unit configurations within the STARDOM platform, allowing maintenance teams to standardize on one spare part number across multiple installed nodes.

Quality Assurance & Global Logistics

Every YOKOGAWA SR1B-045N-1KC unit supplied through siemensplc.com is sourced through verified industrial distribution channels with full traceability documentation. Physical inspection covers label authenticity, housing integrity, connector pin condition, and cross-reference against YOKOGAWA’s published part marking standards. Units showing any indicator of non-OEM origin are rejected at intake — no exceptions.

Shipment originates from Xiamen, Fujian Province, China. Xiamen’s port infrastructure and established freight forwarding ecosystem support DHL Express, FedEx International Priority, and TNT Economy Express for time-critical orders, with sea freight (LCL consolidation or FCL) available for bulk procurement. Standard in-stock dispatch is 1–3 business days from order confirmation. Full export documentation — commercial invoice, packing list, certificate of origin, and customs declaration — is prepared for every international shipment. Anti-static packaging with moisture barrier bags and foam cushioning protects the module during transit. A 12-month warranty from shipment date covers manufacturing defects under normal operating conditions.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
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